DocumentCode :
349442
Title :
A sophisticated FIB system with a new very low energy ion gun for nm-finishing
Author :
Beag, Y.W. ; Gotoh, M. ; Shimizu, R. ; Aihara, R. ; Takahashi, H.
Author_Institution :
Dept. of Appl. Phys., Osaka Univ., Japan
Volume :
2
fYear :
1999
fDate :
36495
Firstpage :
795
Abstract :
A compact very low energy ion gun has been developed for finishing a cross-sectional sample prepared with a focused ion beam (FIB) for transmission electron microscopic observation. This ion gun enables the damaged layers of the cross-sectional sample to be reduced below nanometer thickness. The system allows us to irradiate a sample with FIB and a very low energy ion beam simultaneously and/or alternatively. The ion gun consists of a permanent magnet aided electron impact type ionization cell, extractor, cylindrical retarding immersion lens, and einzel objective lens system. The ions extracted from the ionization cell by the potential differences of 1~1.5 kV to ensure a high current intensity are decelerated through the cylindrical immersion lens and focused onto a specimen surface by the einzel objective lens. The intensities of Ar+ ion beams are ~1 μA at 250 eV and ~2.5 μA at 500 eV. The beam spots for 250 eV and 500 eV ions are ~2.7 mm and ~1.9 mm in diameter, respectively, at a working distance of 40 mm. The damaged layers of ~25 nm thickness on a Si sample prepared with 25 keV Ga+ ions were reduced by finishing with 250 eV and 500 eV Ar+ ions to ~2.1 nm and ~2.8 nm thickness, respectively. High resolution TEM observations of the cross-sectional samples with damaged layers reduced to a thickness of a few nm are also presented
Keywords :
elemental semiconductors; focused ion beam technology; gallium; ion implantation; ion sources; silicon; transmission electron microscopy; Si:Ga; TEM; cross-sectional sample; cylindrical retarding immersion lens; einzel objective lens system; electron impact type ionization cell; focused ion beam system; low energy ion gun; nm-finishing; Art; Electron beams; Electron microscopy; Finishing; Ion beams; Ionization; Lenses; Physics; Power engineering and energy; Transmission electron microscopy;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Ion Implantation Technology Proceedings, 1998 International Conference on
Conference_Location :
Kyoto
Print_ISBN :
0-7803-4538-X
Type :
conf
DOI :
10.1109/IIT.1998.813787
Filename :
813787
Link To Document :
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